Pressure-equalizer for valves.



P. E. SPITZEFL PRESSURE EQUALIZER FOR VALVES APPLICATION FILED NOV. 30.l9l4.

atented Julv 11. 1916.

ourp a;

PURVES E. SPITZER, OF WEST ALLIS, WISCONSIN, ASSIGNOR TOALLIS-CHALIVIERS MANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, ACORPORATION OF DELAWARE.

I v Specification of Letters Patent.

Patented July 11, rain.

' Application filed November 30, 1914. Serial No. 875,190.

To all whom it may concern Be it known that PuRvEs E. Srrrznn, a

citizen of the United States, residing at West Allis, in the county ofMilwaukee and Stateof Wisconsin, has invented a certain 'new and usefulImprovement in Pressure- Equalizers for Valves, of which the follow-;

ing is a specification This invention relates to improvements means forbalancing or equalizing the pres-- sures on valves. I 1

One of the more specific ob]ects s to'provide a device for "equalizingthe pressures on opposed surfaces of large gate valves I prior toopening and closing thereof 1 Another object is to"'pr'ovide means forpositively locking large vaiv in either open or .closed position an openby-pass communication has been establlshed around the valve. U

A further object is to provide a mechanism which -is especiallyapplicable to the main motor actuated gate valves of hydraulic turbineinstallations, for preventing actuation of these valves under abnormalunbalanced pressures.

A clear conception ofan embodiment of the invention may be had byreferring to the drawing accompanylng and formlng a part of thisspecification in which the va-' rious parts are identified by suitablereference characters.

The single figure of the main pipe line to the discharge side 5 thereof.The stem of the main gate 1 is provided with a servo-motor piston 8,which is reciprocable within the servo-motor cylinder 7. The by-pass 6connects the 'inlet side 4 of the main pipe line with the discharge side5 thereof. The flow. or fluid through the bypass 6 is controlled bymeans of a manually operable by-pass'valve2.

The conduits or pipes 9,10, are adapted to admit and exhaust fluid underpressure to the opposite faces of the servo-motor 7 drawing is adiagrammatic sectional plan viewof a gate piston 8. The servo-motoractuating fluid under pressure is admitted from a suitable source, notshown, to the pipes 9, 10, through the conduit or pressure supply pipe11. The servo-motor supply valves 14, 16, control the flow .of fluidfrom the supply pipe 11 to the plpes 9, 10, respectively. The servomotor exhaust valves 13, 15, control the exhaust of fluid fromtheservo-motor cylinder 7 through thepipes 9, 10, respectively. Thepressure exhaust conduit or pipe .12 connects the exhaust valves l3, 15with asuitable exhaust receptacle, not shown.

. The by-pass valve 2 which controls" the flow of fluid through thebypass 6, is operable by means of a stem 21and hand wheel 22' The stem21 is rotatable in a stationary hearing, being fixed againstlongitudinal displacement, and has a screw-threaded end coacting withthe valve 2. The valve stem 21 carries a worm 20 which meshes with videdwith a cam groove 19 which coacts with a roller carried by the endof thevalve stem 17 of the auxiliary valve 3.' The aux: ihary valve 3 controlsthe. flow of fluid through the'conduit or pipe 10 to and from theservo-motor cylinder During the normal operation of the device and withthe main gate 1 in closed position as shown, the inlet side of the pipeline is under pressure while the discharge side 5 may be underconsiderably lower pressure. Wlth the discharge side 5 under lowerpressure, it Wlll be noted that upon operation of the main gate 1, theseating'su'rfaces between the main gate 1 and its casing on thedischarge side 5, will be subjected to considerable wear; In order toprevent such wear, means are provided in the form of the by-pass 6 andby-pass valve 2, for per-' mitting equalization of the pressures in theopposite sides 4, 5, of the main. pipe'line. If the by-pass valve 2 isopened by means .of the hand wheel 22, fluid under pressure passes fromthe side 4"'through the by-pass 6 to the side 5 of. the 'main pipe lineand eventually establishes substantially equal pressures on oppositesides of the main gate 1.

With the device in the position shown, if it is desired to open t he-main valve 1, the supply valve 14: should first be closed and ananticlockwise direction as viewed in the figure, until the abrupt bendin the cam groove 19 is reached. By-this time the bypass valve 2 willhave been almost fully opened and the pressure on opposite sides of themain gate lwill have been substantially equalized. -Upon furtherrotation of l the stem 21, worm andworm wheel 18,

the roller at the end of the auxiliary. valve stem 17 rides along theinwardly extending portion of the cam groove 19 and causes theauxiliary-valve '3 to-suddenly open and to permit fluid under pressureto flow from the pressure inlet pipe 11 through the valve 16 and pipe 10to the chamber below the servo-motor piston 8. The admission of fluidunder pressure'to the lower face of the piston Scauses the piston andthe main gate 1 to move upwardly to open the'main gate and to establishdirect communication between the sides 1, 5, 'ofthe pipe line. Duringopening movement of the fluid in the'upper chamber of the cylthemaingate 1,

inder 7 is forced through the 13 and pipe 12 to the exhaust.

If it is desired to. close the main valve 1, the pressure supply valve14 should be pipe 9, valve opened and the exhaust valve 13 closed asshown, whilethe pressure supply valve 16 should be closed andthe'exhaust valve 15 opened. If the by-pass valve 2 is open at the timeit is desired to close the main valve 1, the proper setting of thevalves 13, 14, 15, 16, will automatically cause the main gate 1 toclose. If, however, the by-pass valve 2 is closed atthe time closing ofthe main gate 1 is desired, the auxiliary valve 3 will also be closed asshown, and the fluid confined below the servo-motor piston 8 will not bepermitted to escape to exhaust. The by-pass valve 2 must therefore beopened before closing of the main gate 1 is permitted, opening of theby-pass valve resulting in openingof the auxiliary valve 3 and in theestablishment cation between the servo-motor and exhaust through thepipe 10, valve 15 and pipe 12.

It will thus be noted thatthe main gate 1 cannot be either opened orclosed until after the by-pass valve 2 has been opened, thus insuringestablishment of substantiallyequalf pressures inthe -sides 4, 5,*o'themain pipe during manipulation of the Inain gate 1. This equalization ofthe" -gressures eliminates the excessive" Wear on--the' valve seat whichwould result from -having,the main gate operated under abnormalunbalanced for equalizing the pressure said main valve when the 'passaround said main valve,

'tuating said main va ment of actuating the auxiliary valve 3 is alsomerely one of many arrangements which might'be employed to accomplishthe same result.

It should be understoodthat it is not desired to be limited to the'exactdetails of construction shown and described, for obvious modificationswill occur to a person skilled in the art. h It is claimed and desiredto secure by Letters Patent,

1.'In combination, a main valve, means on opposite sides of said mainvalve, pressure operated means for actuating said main valve, and meansfor positively preventing admission I of pressure to said operatingmeans for actuation of said main valve when the pressures on oppositesides of said main valve are not equalized.

2. In combination, a main valve, means for equalizing the pressures onopposite sides of said main valve, pressure operated means for actuatingsaid main valve, and means operable by said equalizing means forpositively preventing admission of pressure to said operating means foractuation of said main valve.

3. In. combination, a main valve, means for equalizing the pressures onopposite sides of said main valve, pressure operated means for actuatingsaid main valve, and means for positively preventing admission ofpressure to said operating means to open pressures on opposite sides ofsaid valve are not equalized. 4. In combination, a main valve, a by-passvalve, pressure operated means for actuating said main valve, and meansfor positively preventing. admission of pressure'to said operating meansfor actuation of said main h valve when said by-pass valve is closed. offree commune.

5. 'In combination, a main valve, a byservo-motor for actuating saidmamvalve, an auxiliary valve for positively preventing admission ofpressure. to said operating means for actuation of said main valve, andmeans for locking said auxiliary valve in closed position until aftersaid by-pass has been opened. 6. In combination, a main valve, a hypassvalve', pressureoperated means for acve, and an auxiliary valve operableby said bypass valve for a hydraulic positively preventing admission ofpressure for equalizing the-pressures on opposite sides of saidmainlvalve, pressure operated means ,for aetuating sald mam valve,and'ineans tivelylpreventing admission of pressure-to saidoperatingmeans for operation of said main'valve when saidmain valve is closed.

fluid through'said by-pa'ss, a hydraulic servoopened. I operable by;said equalizing means fo'rposimotor for aetuathig saidniain valve,' a11auxiliary valve for positively preventing admission of liquid to sa1dservo-motor to open said main valve, and means for look;

ing said auxiliary valve in closed position until after said: luv-passvalve has been In testlmony whereof, the signature of the inventor isaflixed hereto-in the presence of two Witnesses. I

- PURVES' E. SPITZER.

Witnesses: I

W; H. LLEBER, I J. J. KANE.

